Category Archives: Cummins 4BT

Remove the drive belt. 15 mm Remove crankshaft pulley/vibration damper. (On six cylinder engines, a vibration damper is integral to the crankshaft pulley.)  

Install the piston and connecting rod assemblies. Refer to Procedure (7-10). Install the lubricating oil pan. Install the cylinder head. Refer to Procedure (7-07). Fill the lubricating oil pan. Fill the engine with coolant. Operate the engine to normal operating temperature and check for leaks.  

Use a strong soution of hot water and laundry detergent to clean the cylinder bores. Rinse the cylinder bores until the detergent is removed. Dry the cylinder block with compressed air. Be sure to remove the tape covering the tappet and lubricating oil holes after the cleaning process is com­plete. Check the cylinder bore cleanliness… Read More »

Deglazing gives the cylinder bore the correct surface finish required to seat the rings. NOTE: New piston rings may not seat in glazed cylinder bores. Wrap the connecting rod journals with a clean cloth. Cover the cloth with waterproof tape. Place a clean shop towel around the top main bearing saddle to deflect water and… Read More »

Measure the cylinder bore diameter at 25.4 mm [1 in] and 170.7 mm [5.5 in] from the top of the cylinder block. Bore I.D. Max – 102.116 mm [4.0203 in] Bore out of round – .035 mm [.0015 in] Bore taper – .076 mm [.003 in] NOTE: Do not proceed with in-chassis overhaul if the… Read More »

Drain the coolant. Remove the cylinder head. Refer to Procedure (7-07). Drain the lubricating oil. Remove the lubricating oil pan. Remove the piston and connecting rod assemblies. Refer to Procedure (7-10).  

Caution: Use care so the screwdriver does not damage the crankshaft or cylinder block. NOTE: The front main, No. 1, does not have a hole in the journal so the pin cannot be used to replace the bearing. Use a flat blade screwdriver. Gently bump the end of the bearing to loosen it from the… Read More »

Remove all main bearing caps except the No. 1 and 7 main bearing cap for 6 cylinder engine. The 4 cylinder engine is depicted in the illustration. Use a pin to roll out the upper bearings from between the crankshaft and cylinder block. To make a pin, grind a 6 mm capscrew to the dimensions… Read More »

Drain the lubricating oil and remove the lubricating oil pan. NOTE: Before removing the main bearing caps, make cer­tain that the caps are clearly marked for their location on the lubricating oil cooler side of the main bearing cap. Perform a visual inspection of the main bearings and crankshaft journals. Remove the No. 2 and… Read More »

NOTE: Used bearings must be installed in the same locationfrom which they were removed. Use Lubripiate 105® or equivalent to coat the inside di­ameter of the bearing shell. Install the upper bearing shell in the connecting rod with the tang of the bearing in the slot of the connecting rod. Install the bearing shell in… Read More »